Magnetic fields in merging spirals - the Antennae

We present an extensive study of magnetic fields in a system of merging galaxies. We obtained for NGC4038/39 (the Antennae) radio total intensity and polarization maps at 8.44, 4.86 and 1.49GHz using the VLA in the C and D configurations. The radio thermal fraction was found to be about 50% at 10.45GHz, higher than in normal spirals. The mean total magnetic fields in both galaxies are about two times stronger (20microG) than in normal spirals. However,the degree of field regularity is rather low, implying tangling of the regular component in regions with interaction-enhanced star formation. Our data combined with those in HI, Halpha, X-rays and in far infrared allow us to study local interrelations between different gas phases and magnetic fields. We distinguish several radio-emitting regions with different physical properties and at various evolutionary stages. The whole overlapping region shows a coherent magnetic field structure, probably tracing the line of collision between the arms of merging spirals while the total radio emission reveals hidden star formation nests. The southern part of it is a particularly intense merger-triggered starburst. Highly tangled magnetic fields reach there strengths of 30microG, even larger than in both individual galaxies, possibly due to compression of the original fields pulled out from the parent disks. In the northeastern ridge, away from star-forming regions, the magnetic field is highly coherent with a strong regular component of 10microG tracing gas shearing motions along the tidal tail. Modelling Faraday rotation data show that we deal with a three-dimensionally curved structure of magnetic fields, becoming almost parallel to the sky plane in the southeastern part of the ridge.Comment: Accepted for publication in AA, 16 pages including 16 figures, high-res version at http://www.oa.uj.edu.pl/~chris/publ/4038.ps.g

Persuading developers to buy into software process improvement: a local opinion and empirical evidence

This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.---- Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.In order to investigate practitioners’ opinions of software process and software process improvement, we have collected a large volume of qualitative evidence from 13 companies. At the same time, other researchers have reported investigations of practitioners, and we are interested in how their reports may relate to our evidence. Thus, other research publications can also be treated as a form of qualitative data. In this paper, we review advice on a method, content analysis, that is used to analyse qualitative data. We use content analysis to describe and analyse discussions on software process and software process improvement. We report preliminary findings from an analysis of both the focus group evidence and four publications

Persuading developers to buy into software process improvement: an exploratory analysis

In order to investigate practitioners' opinions of software process and software process improvement, we have collected information from 13 companies, in a variety of ways i.e. the use of Repertory Grid Technique, survey and focus group discussions. Both the Repertory Grid Technique and the focus group discussions (43 discussions occurred, in total) produced a large volume of qualitative data. At the same time, other researchers have reported--investigations of practitioners, and we are interested in how their reports may relate to our own. Thus, other research publications can also be treated as a form of qualitative data. In this paper, we review advice on a method, content analysis, that is used to analyse qualitative data. Content analysis is a method for identifying and classifying words and phrases used in--ordinary language. We use content analysis to describe and analyse discussions on software--process and software process improvement. We report preliminary findings from an analysis--of both the focus group evidence and some publications. Our main finding is that there is an--apparent contradiction between developers saying that they want evidence for software process improvement, and what developers will accept as evidence. This presents a serious problem for research: even if researchers could demonstrate a strong, reliable relationship between software process improvement and improved organisational performance, there would still be the problem of convincing practitioners that the evidence applies to their particular situation

Using software development progress data to understand threats to project outcomes

Peer reviewe

The Greisen Equation Explained and Improved

Analytic description of the evolution of cosmic ray showers is dominated by the Greisen equation nearly five decades old. We present an alternative approach with several advantages. Among the new features are a prediction of the differential distribution, replacing Greisen's form which fails to be positive definite. Explicit comparison with Monte Carlo simulations shows excellent agreement after a few radiation lengths of development. We find a clear connection between Monte Carlo adjustment of Greisen's form and underlying physics, and present a concise derivation with all steps explicit. We also reconstruct the steps needed to reproduce Greisen's approximate formula, which appears not to have been published previously.Comment: 8 pages, 7 figures, revised version, accepted for publication in Phys. Rev.

The honorable fraternity of moving merchants: Yankee peddlers in the Old South, 1800--1860

Yankee peddlers were ubiquitous in the countryside and in the imagination of the Old South. Social and economic forces pushed young men off the farms of rural New England and pulled them into an expanding, national market. The shortage of land for a burgeoning population spurred the exodus from the countryside, while the lure of profits from a vocation with low entry costs attracted many young men who preferred seeking the main chance in the commercial marketplace to a state of protracted dependency as a farm hand, a factory operative, or an outwork producer. Hired by firms to peddle clocks, tinware, and other notions, their experiences in the marketplace transmogrified these deracinated New England farm boys into sharp, itinerant traders. In the course of this transformation, these migrant workers from New England were indelibly marked by the culture in which they were raised, even as they moved away from familiar values to embrace an emerging market creed.;The thousands of young men from New England who peddled in the South between 1800 and 1860 provided rural southern households direct access to consumer goods. They joined native southern petty merchandisers---hucksters, cake bakers, watermen and groggery keepers---in an interracial, face-to-face economy whose actions threatened the fixed ranks and organic hierarchy of slave society. The Yankee peddler gradually became a more threatening figure to southern planters. Antebellum southern sensibilities towards northern society and market institutions evolved from Southerners\u27 real and fictionalized encounters with Yankee peddlers. Virginia planters hated debt, even as they continued to consume goods they could not afford, and rather than fault themselves for high living, they blamed the agents of consumer desire---Yankee peddlers---for conspiring with women and enslaved dependents to undermine their authority and worsen their economic plight. Southern caricatures of the Yankee peddler put a face on the impersonal forces of the national marketplace that intruded into traditional exchange networks. The fictive Yankee peddler\u27s violation of the southern home elucidates the apprehensions antebellum southern society experienced as it was integrated into the national market and edged towards secession

Risk of Cardiovascular Disease and Events in Transgender Patients Undergoing Hormone Therapy

The number of transgender individuals currently being prescribed cross-sex hormone replacement therapy (CSHRT) is currently at an all-time high, but the short- and long-term effects that those medications have upon the cardiovascular system remains largely unknown. To examine the effect that CSHRT has on the cardiovascular system, this review synthesizes the results of five different studies on CSHRT and cardiovascular outcomes in transgender individuals. The report also examines differences in cardiovascular outcomes associated with different dosages and preparations of CSHRT. This review notes that transgender women are at highest risk of adverse cardiovascular events, with those taking high-dose oral estrogen being up to 45 times more likely to experience a thromboembolitic event. The evidence surrounding transgender men is less conclusive, but does suggest a slightly increased risk of acute and chronic cardiovascular issues. These results suggest that transgender individuals taking CSHRT may be at an increased risk for adverse cardiovascular outcomes. Healthcare providers working with transgender patients should be aware of dosages and routes of CSHRT that carry fewer risks yet achieve similar patient outcomes. Patients must also be educated on these risks while being guided to develop healthy cardiovascular habits

High-temperature synthesis, single-crystal X-ray and neutron powder diffraction, and materials properties of Sr3Ln10Si18Al12O18N36 (Ln = Ce, Pr, Nd)

The novel oxonitridoaluminosilicates (sialons) Sr3Ln10Si18Al12O18N36 (Ln = Ce, Pr, Nd) were obtained by the reaction of the respective lanthanide metals with Si(NH)2, SrCO3, and AlN using a radiofrequency furnace at temperatures between 1550–1650°C. The crystal structures of the isotypic sialons were determined by single-crystal X-ray investigations (Sr3Ce10Si18Al12O18N36: I3m, Z = 2, a = 1338.2(2) pm, R1 = 0.0333; Sr3Pr10Si18Al12O18N36: a = 1334.54(6) pm, R1 = 0.0296; Sr3Nd10Si18Al12O18N36: a = 1332.85(6) pm, R1 = 0.0271) and in the case of Sr3Pr10Si18Al12O18N36 with powder neutron diffraction as well. The three-dimensional sialon network is built up by SiON3, SiN4, and AlON3 tetrahedra. Besides the bridging O and N atoms of the sialon network there are isolated O2− which are tetrahedrally coordinated by Sr and Ln. The crystallographic differentiation of Si/Al and O/N seemed to be possible by a careful evaluation of the single-crystal X-ray diffraction data combined with lattice energy calculations using the MAPLE concept (Madelung Part of Lattice Energy). In the case of Sr3Pr10Si18Al12O18N36 the differentiation of O and N and the proposed ordering was completely confirmed by powder neutron diffraction

Jet Fragmentation via Recombination of Parton Showers

We study hadron production in jets by applying quark recombination to jet shower partons. With the jet showers obtained from PYTHIA and augmented by additional non-perturbative effects, we compute hadron spectra in e+ + e-collisions at sqrt(s)=200 GeV. Including contributions from resonance decays, we find that the resulting transverse momentum spectra for pions, kaons, and protons reproduce reasonably those from the string fragmentation as implemented in PYTHIA.Comment: 4 pages, 3 figures, contribution to Nucleus-Nucleus Collisions 201